http://www.youtube.com/watch?v=StG14irO3WM

From the login screen, you should have a class selection. One class is the knight, that fights and does knightly stuff, and the other is the Roomba, which roams Haven searching for dust. Knights must step around players playing as Roombas, as if they hold still for too long, the Roomba-players can hold onto them and drag them down and hold them there. Also, if the knight steps on a roomba, the roomba might break. Knights must also save snipes from roomba players, which will eat them.